<p>I’m not sure if it is common. In my field, it very much depends on the school and their budget. Also at some schools, you are invited before getting an offer; at others you are flown in after the offer. These visits can serve different goals.</p>
<p>At our school, after doing skype interviews, we will fly in folks from anywhere- often the other side of the world- for them to meet us and us to meet them (before making offers). Given the cost to a PhD program to fund a student for so many years (any good school is covering a students tuition and providing a stipend), it is a very small investment that I think is worth making. It’s just like getting a job really.</p>
<p>I’m surprised he’s having this opportunity given the record you describe. But what do you consider a low GPA for an undergrad in chemistry from his university? We can readily discount an overall lower GPA if the latter years are strong and the core courses are strong or if the school is known for being particularly tough. And even more so if one has high test scores and great letters. Also what do you mean by internships? Most students accepted into good grad schools will participate in research as undergrads, not necessarily paid and not called an internship. I guess it is quite possible you don’t know all the details of his record.</p>